Operations and Science Instrument Support - Command and Control
The Operations and Science Instrument Support - Command and Control package (OASIS-CC) provides many functions necessary to monitor and control spacecraft and their scientific instruments. Developed by the Laboratory for Atmospheric and Space Physics (LA
SP) at the University of Colorado at Boulder, OASIS-CC communicates between users and their instruments during all phases of instrument development and use: testing, integration, and operations (The term "instruments'' refers to anything OASIS-CC communi
cates with - instruments, spacecraft, test equipment, and ground support equipment.). It receives instrument telemetry and extracts the individual data items, translates user commands into binary or ASCII formats expected by the instrument, and formats d
ata for display to the user.
OASIS-CC also helps users monitor instrument status. The system verifies that incoming data is within prescribed limits, alerts users to problems in incoming data, and can respond automatically to problems as they arise.
OASIS-CC records all data as it is received in unformatted binary data files. OASIS-CC also strips science data from the incoming data stream, and stores it in files or forwards it to other systems for use in science analysis.
OASIS-CC has several subsystems. Each subsystem performs a specific set of functions, then passes the results to another subsystem, an external system, or the user. These subsystems are tailored for particular instruments by adding information to databa
se tables. Database tables tell OASIS-CC the structure of incoming data and the functions to employ while processing and displaying the data.
OASIS-CC has these major subsystems:
- Data Handling
- Command
- External Communications
- Bridge
- Bus Communications
- User Interface (TAE+)
- Display
- Database
Data Handling converts and processes data entering OASIS-CC from an instrument or a spacecraft.
Data Handling converts new data values into human-readable formats. Two basic types of translations are made. Measurements specifying a small number of states are converted to mnemonics like ON or OFF. Numerical values are converted from simple integer
s into floating point values expressed with their units of measure - 1.23 volts or 73.5 meters.
Data Handling provides the most common types of processing performed on instrument and spacecraft data. "Limit checking" ensures that measurements are within specified operating ranges. "State checking" ensures that devices are in proper operating confi
guration. Equation solutions can be performed to derive new data values from existing data values.
Once processing and checking has occurred, Data Handling stores new data values for later use and, if needed, sends them to Display and to other subsystems for immediate use.
Data Handling is tailored by setting up tables that
- define data items used by the application.
- define instrument-supplied conversions from raw data numbers to calibrated numbers expressed in engineering units or states.
- specify limits of valid values for data items and actions to take if those limits are exceeded.
- specify equations to solve to derive new data items.
Command translates user entered command statements into the binary or ASCII representations the instrument expects to receive. Command can check that the necessary prerequisites for issuing a command have been satisfied and verify proper command executio
n.
The Command subsystem issues a command by passing it to External Communications, which oversees transmission.
External Communications handles computer-to-instrument and computer-to-computer communications. This communication occurs over dedicated data links or networks.
External Communications provides data formatting for transmission, error control and recovery, when applicable. It accepts frames or packets of data containing measurements from external systems, strips out individual measurements, and passes them to Da
ta Handling for further processing.
Bridge provides the ability to generate either formatted or unformatted collections of instrument data after they are processed by Data Handling. Formatted data can either be transmitted to other computers via External Communications, or saved in a file.
Bridge data can be read by external, off the shelf analysis programs.
Bus Communications extends OASIS-CC external communications capabilities to include control of equipment connected to an IEEE-488 data bus. The IEEE-488 data bus often controls ground support and laboratory test equipment.
OASIS-CC uses the Colorado System and Test Operations Language (CSTOL, pronounced SEESTALL). CSTOL is not a programming language. Instead, it resembles the command languages one encounters when signing onto a system. These general-purpose command langu
ages include DCL for VAX/VMS, C-Shell and Bourne Shell for Unix and the MS/DOS command language. While these languages perform operations like listing files in a directory and displaying the contents of text files, CSTOL is designed for scientists, engin
eers, and ground controllers. Built as a test for many of the requirements for the Space Station User Interface Language, CSTOL provides functions necessary to develop, test, and operate spacecraft and their payload.
In addition to the CSTOL language, the OASIS-CC user interface employs the Transportable Application Environment Plus (TAE+), a Motif-compliant, portable environment for developing and running interactive, window, text and graphical object-based applicati
on systems. The TAE+ workbench, an intuitive tool that supports the design and layout of an applications user interface, is augmented by LASP. This augmented workbench, called the Action Workbench, facilitates the linkage between the interface and OASIS
-CC. It generates Ada or C code, then links that code with OASIS-CC libraries to generate an executable program. TAE+ allows the user to develop very simple or elaborate user interfaces.
Display provides linkage between the OASIS-CC Data Handling subsystem and the TAE+ graphical interface.
Display also manages windows that are used for displaying system messages, commands, procedures, reports, CSTOL input and certain system alerts.
Database manages all database tables used by OASIS-CC and provides user and system access to those tables. To adapt OASIS-CC to an application, the system manager tailors the database and creates a graphical interface.
OASIS-CC evolved from two earlier software programs developed to monitor and control spacecraft and the scientific instruments they carry. The original program, the Multi Satellite Operations Control Center or MSOCC was developed by Goddard Spaceflight
Center (GSFC). Later, the Solar Mesosphere Explorer (SME) control center was developed using the MSOCC as its basis. LASP based many of the functional requirements for OASIS-CC on the SME control center design as well as the additional requirements for:
- Ease of Use
- Portability between applications and hosts
- Life Cycle Use
OASIS-CC was made easier to use by the implementation of a flexible user interface based on GSFC's Transportable Application Environment Plus (TAE+) and an upgraded test and operation language based on GSFC's STOL; the Colorado System Test and Operations
language (CSTOL).
The X-11 based, Motif compliant interface employs a workbench to design and test the user interface and features data-driven objects. CSTOL simplifies use by using a distinctly English-like syntax and a command syntax that is modifiable by the user, by s
upporting engineering units, and by permitting database queries.
This requirement constitutes portability between different applications and different computer environments. Portability between applications is supported using table driven software. OASIS-CC also employs standard communication protocols (TCP/IP and RS
232 for example).
Portability between computer environments is achieved by coding in the Ada language and implementing an X-11 based user interface.
OASIS-CC can be used throughout the project life cycle, during functional testing, calibration, systems integration and testing and on-orbit operations. This breadth of use is possible for several reasons. One, OASIS-CC software is table driven. Two, O
ASIS-CC simultaneously handles multiple command and data streams, both incoming and outgoing. Three, OASIS-CC provides data distribution services.
OASIS-CC comes with a broad variety of technical support. This support includes:
- Utility Programs
- Documentation
- A Technical Support Office
- Anomaly Reporting and Configuration Management
- Release Documentation
Several of these programs are database-related. Load_Database loads an ASCII representation into an internal representation, while Dump_Database reverses that process. Report_Database converts an internal representation to a report format. GSFC has dev
eloped a graphical database builder which employs a TAE+ interface for the Earth Observing System (EOS) project. A parser-related program, Convert_Table, converts ASCII tables into their internal representations.
OASIS-CC comes with the following documentation developed at LASP:
Four types of support are available with OASIS-CC. This support includes phone support for the application developer, an applications developer class, specific code development, and application development.
The OASIS-CC anomaly reporting mechanism is available via the Internet. This mechanism allows users to report anomalies or request enhancements. Each report is automatically assigned a number which users may reference to track their reports. These repo
rts are also used to support configuration management.
Each report consists of three parts: a user-provided description, a problem statement and solution description developed by the support office team, and a disposition field.
New releases are fully documented in the following release notes:
Most Recent:
oasis_v2.0514_7.1.pdf (version: V02.05.14(7.1), released: 02/07/07)
Old:
OASIS-CC is used in a variety of ways, namely sub-instrument testing, integration and testing and on-orbit operations.
Following is a list of some projects that currently use OASIS-CC:
- LASP applications
- STRV 1A and 1B: Flight Operations
- SNOE: Spacecraft I&T and flight operations
- Cassini / UVIS: Instrument bench testing, I$T and flight operations
- Non LASP applications
- ORBCOMM (OSC): Spacecraft I&T and flight operations
- GFO (Ball): Spacecraft I&T
- QuikBird (Ball): Spacecraft I&T
- QuikScat (Ball): Spacecraft I&T and flight operations
- EOS/am (Lockheed): Spacecraft I&T
- Landsat 7 (Lockheed): Spacecraft I&T
- Gravity Probe B (Lockheed / Stanford): Spacecraft I&T and flight operations
- Lunar Prospector (Lockheed): Spacecraft I&T
- CRSS (Lockheed): Spacecraft I&T and ground segment
- MOPITT (Comdev / U of Toronto): Instrument bench testing
- MODIST (SBRC): Instrument bench testing
- ARGOS (NRL): Instrument bench testing
Software Cost Schedule
Support Cost Schedule
License Agreement
Contact:
- Alain Jouchoux (firstname.lastname@lasp.colorado.edu)
- Gail Tate (firstname.lastname@lasp.colorado.edu)
Last updated 02/10/07